Will both versions of this driver exist in the same kernel build?  For
example the iop-adma driver supports iop13xx and iop3xx, but we select
the archtitecture at build time?  Or, as I assume in this case, will
the
two (maybe more?) ppc4xx adma drivers all be built in the same image,
more like ioatdma?

[Marri] We select the architecture at build time.

In the latter case I would recommend a file structure like:

drivers/dma/ppc4xx/adma.c
drivers/dma/ppc4xx/adma_440spe.c
drivers/dma/ppc4xx/adma_460ex.c

With patches to move the chipset specific pieces to their own file.
Minimizing the code churn in adma.c, or at least showing a progression
of what is unique and needs to be moved.

This would be similar to how ioatdma is structured and compiles a
single
driver to cover the three major hardware revisions.

[Marri]Looks like this driver is similar to iop-adma driver.